C Compiler

A C compiler that compiles a subset of the C language and that extends it to support Object Oriented Programming.
The current syntax grammar for the language can be found here grammar. The modified LL(K) left parsable syntax can be found here llk_grammar.
The abstract syntax nodes for the current compiler implementation are in the following grammar as_grammar.
The compiler is stricter than the standard C as it is strongly typed and will never do autocasting (typing rules).

The compiler targets MIPS, so we will the Mars MIPS simulator to run compiled code and tests.
The register allocator currently uses Chaitin's algorithm and only uses $s and $t architecture registers.

Built-in functions

void print_s(char* s);
void print_i(int i);
void print_c(char c);
char read_c();
int read_i();
void* mcmalloc(int size);

Example of a C file that can be compiled:

#include "minic-stdlib.h"

class Counter {
    int value;

    void init(int start) {
        value = start;
    }

    void increment() {
        value = value + 1;
    }

    void print() {
        print_s((char*)"Counter value: ");
        print_i(value);
        print_s((char*)"\n");
    }
}

class FancyCounter extends Counter {
    void increment() {
        // Increments by 2 instead of 1
        value = value + 2;
    }

    void print() {
        print_s((char*)"FancyCounter value: ");
        print_i(value);
        print_s((char*)"\n");
    }
}

void main() {
    class Counter c;
    class FancyCounter fc;
    int i;

    c = new class Counter();
    fc = new class FancyCounter();

    c.init(0);
    fc.init(10);

    i = 0;

    while (i < 3) {
        c.increment();
        fc.increment();
        c.print();
        fc.print();
        i = i + 1;
    }
}

Requirements

A recent JDK version (version 21 or higher)

$ javac -version

Any recent Apache Ant as the build system

$ ant -version

• https://ant.apache.org/manual/install.html
• brew for macos

Building the Compiler

We will use the Ant build file (build.xml)

$ ant build

This command outputs compiler in a directory called bin within the project structure. Thereafter, you can run the compiler from the commandline:

Usage: java Main4 pass inputfile [outputfile]
where pass is either: -lexer, -parser, -ast, -sem, -gen [naive|colour], -regalloc naive|colour
if -ast, -gen or -regalloc is chosen, the output file must be specified

You can clean the bin directory by typing:

$ ant clean

This command effectively deletes the bin directory.

Running the Compiler

To run the compiler, use the following command:

$ java -cp bin Main4 -gen colour path_to_c_source_file path_to_asm_output_file

Run the asm file on the MIPS simulator

$ java -jar ./description/Mars4_5.jar sm nc me path_to_asm_file

Running tests

If you are using macos, you need to install extra packages using brew as we use timeout

$ brew install coreutils

By default the shell script will run on bash but running it on zsh is better as the latter supports displaying colors on the terminal. So if you want to use zsh you need to modify the first two lines in the script located at ./src/test/auto-test.sh

#!/bin/zsh
INTERPRETER="ZSH"
...

To run the test script

$ chmod +x ./src/test/auto-test.sh
$ ./src/test/auto-test.sh